Optical coupler for vertical optical coupling

Abstract

An optical coupler and a method performed by the optical coupler are described. The optical coupler includes an interlayer dielectric, a waveguide disposed within the interlayer dielectric, and an epoxy disposed on the interlayer dielectric and in the first cavity such that the epoxy defines an upper surface and a bottom surface. The interlayer dielectric includes a first surface and a second surface coupled to the first surface. The first surface and the second surface define a first cavity in the interlayer dielectric. The waveguide emits an optical signal through the first surface. The bottom surface is positioned between the interlayer dielectric and the upper surface. The epoxy directs the optical signal from the first surface to the second surface. The second surface and the epoxy direct a first portion of the optical signal through the upper surface.

We claim: 
     
         1 . An optical coupler comprising:
 an interlayer dielectric comprising a first surface and a second surface coupled to the first surface, wherein the first surface and the second surface define a first cavity in the interlayer dielectric;   a waveguide disposed within the interlayer dielectric, wherein the waveguide is arranged to emit an optical signal through the first surface; and   an epoxy disposed on the interlayer dielectric and in the first cavity such that the epoxy defines an upper surface and a bottom surface, wherein the bottom surface is positioned between the interlayer dielectric and the upper surface, wherein the epoxy is arranged to direct the optical signal from the first surface to the second surface, and wherein the second surface and the epoxy are arranged to direct a first portion of the optical signal through the upper surface.   
     
     
         2 . The optical coupler of  claim 1 , wherein the first surface and the second surface are positioned at different angles relative to the bottom surface. 
     
     
         3 . The optical coupler of  claim 1 , wherein the second surface is curved. 
     
     
         4 . The optical coupler of  claim 1 , wherein the second surface and the epoxy direct the optical signal through the upper surface. 
     
     
         5 . The optical coupler of  claim 1 , further comprising a coating disposed on the second surface, wherein the coating is arranged to direct the first portion of the optical signal through the upper surface. 
     
     
         6 . The optical coupler of  claim 5 , wherein:
 the interlayer dielectric further defines a third surface and a fourth surface coupled to the third surface;   the third surface and the fourth surface define a second cavity in the interlayer dielectric;   the coating and the second surface are arranged to direct a second portion of the optical signal through the third surface;   the epoxy is further arranged to direct the second portion of the optical signal to the fourth surface; and   the fourth surface and the epoxy are arranged to direct the second portion of the optical signal through the upper surface.   
     
     
         7 . The optical coupler of  claim 5 , wherein the coating comprises a metal coating. 
     
     
         8 . The optical coupler of  claim 5 , wherein the coating comprises a dielectric coating. 
     
     
         9 . The optical coupler of  claim 1 , wherein the waveguide comprises a spot size converter. 
     
     
         10 . The optical coupler of  claim 1 , wherein a refractive index of the epoxy is higher than a refractive index of the interlayer dielectric. 
     
     
         11 . A method comprising:
 emitting, by a waveguide disposed within an interlayer dielectric comprising a first surface and a second surface coupled to the first surface, an optical signal through the first surface, wherein the first surface and the second surface define a first cavity in the interlayer dielectric;   directing, by an epoxy disposed on the interlayer dielectric and in the first cavity such that the epoxy defines an upper surface and a bottom surface, the optical signal from the first surface to the second surface, wherein the bottom surface is positioned between the interlayer dielectric and the upper surface; and   directing, by the second surface and the epoxy, a first portion of the optical signal through the upper surface.   
     
     
         12 . The method of  claim 11 , wherein the first surface and the second surface are positioned at different angles relative to the bottom surface. 
     
     
         13 . The method of  claim 11 , wherein the second surface is curved. 
     
     
         14 . The method of  claim 11 , wherein the second surface and the epoxy direct the optical signal through the upper surface. 
     
     
         15 . The method of  claim 11 , further comprising directing, by a coating disposed on the second surface, the first portion of the optical signal through the upper surface. 
     
     
         16 . The method of  claim 15 , wherein:
 the interlayer dielectric further comprises a third surface and a fourth surface coupled to the third surface;   the third surface and the fourth surface define a second cavity in the interlayer dielectric; and   the method further comprising:
 directing, by the coating and the second surface, a second portion of the optical signal through the third surface; 
 directing, by the epoxy, the second portion of the optical signal to the fourth surface; and 
 directing, by the fourth surface and the epoxy, the second portion of the optical signal through the upper surface. 
   
     
     
         17 . The method of  claim 15 , wherein the coating comprises a metal coating. 
     
     
         18 . The method of  claim 15 , wherein the coating comprises a dielectric coating. 
     
     
         19 . The method of  claim 11 , wherein a refractive index of the epoxy is higher than a refractive index of the interlayer dielectric. 
     
     
         20 . An optical coupler comprising:
 an interlayer dielectric comprising a first surface and a second surface that define a cavity in the interlayer dielectric; and   an epoxy disposed on the interlayer dielectric and in the cavity, wherein the epoxy comprises an upper surface and a bottom surface positioned between the interlayer dielectric and the upper surface, wherein:
 the epoxy is arranged to direct an optical signal from the first surface to the second surface; and 
 the second surface and the epoxy are arranged to direct the optical signal through the upper surface.